The present invention generally concerns the field of interbody implants with which it is possible to obtain fusion of two adjacent vertebrae when the disc separating them has been damaged, and more specifically, but not exclusively, it concerns the implants commonly referred to as “interbody cages” or “intersomatic cages” which are intended to receive a bone graft and to maintain the latter in place during the fusion, after partial excision of the damaged disc.
When a disc separating two vertebrae has degenerated and interbody fusion is necessary, this can be obtained by implanting interbody cages in cavities formed in the degenerated disc. The interbody cages are often fitted by the anterior route, in which case it is possible only to provide a single cage of this type, implanted in the central region of the disc. However, when the lumbar region is involved, an approach by the posterior route is possible on account of the fact that the nervous system there is less dense than in the other regions of the spine. There is therefore less risk of damaging the nervous system there during the surgical intervention. Nevertheless, the presence of the medullary canal in practice requires the use of two small sized interbody implants that are symmetrically arranged relative to the axis of the spine. These bilateral implants are separate components that are not connected to one another. There is therefore a risk of relative displacement or expulsion of the implants, especially since an implant of small size is less stable, in particular rotationally less stable, than an implant of larger size.